[1]} predicted two ultraincompressible, superhard materials, ReWC2 and Mo0.9W1.1BC. The former was synthesized as ReWC0.8 due to unreacted graphite in ReWC2 and is a brand-new ultraincompressible, high-hardness material. Mo0.9W1.1BC had been previously studied in the literature and was further confirmed as an inexpensive, earth-abundant, ultraincompressible hard material. They used svm of 2572 elastic moduli training datapoints from the Materials Project database [2]} and 150 descriptors built from arithmetic operations on compositional and structural properties. Training data was curated from an original set of 3248 elastic moduli entries by eliminating inaccessible phases at ambient pressure and temperature and removing unreasonable entries with e.g. negative values, among other restrictions. While the full descriptor set was used for prediction, for perspective, descriptors were fed through a ga-based fs algorithm, indicating that 52;44 of the descriptors were essential for Bulk modulus (\(B\) ) and shear modulus (\(G\) ), respectively. Both \(B\)  and \(G\)  correlate positively with hardness and are used as proxies in the approach. Careful attention is paid to trends of errors relative to the compound type being predicted; for example, metallic/covalent bonding materials general exhibit lower error than highly ionic compounds. The svm model predicts \(B\)  and \(G\)  for  120000 binary, ternary, and quaternary inorganic solids in Pearson's Crystal Database[3]} with rmsecv of 17.2; 16.5, respectively. ReWC2 and Mo0.9W1.1BC are identified as potential high hardness candidates, having the highest predicted \(B\)  and \(G\)  out of all ternary (ReWC2) and quaternary (Mo0.9W1.1BC) candidates, and were amenable to synthesis via ambient pressure arc melting. Due to presence of unreacted graphite peaks in powder xrd experiments of ReWC2, eventually ReWC0.8 was settled on for testing. High-pressure dac experiments confirmed ultraincompressibility and Vicker's microhardness experiments confirmed superhardness at low loads, 40 3; 42 2 for ReWC0.8 and Mo0.9W1.1BC, respectively.
